Barbara Jean Gilbert, the Prince George's County woman who killed her husband after a 17-year marriage filled with violent fights and infidelity on his part, was set free yesterday after serving 124 days of her sentence.

A Circuit Court review panel overturned the maximum 8-year sentence that had been imposed July 12 by one of the county's senior judges.

Gilbert, 36, sobbed uncontrollably as Judge Robert H. Woods announced that the three-judge panel had voted 2 to 1 to suspend her sentence.

"Judge (Audrey E.) Melbourne and I believe that we must look to the crime the jury found her guilty of," Woods said as Gilbert, her parents and her three children listened. "What preceded that decision is not what we had to consider.

"Involuntary manslaughter means the killing was unintentional," he continued. "We are aware of the purposes of sentencing and all three of us agree that there is no need for rehabilitation in this case." The third man on the panel was Judge William H. McCullough, who recommended that Gilbert serve four years.

Gilbert had been sentenced by Judge Samuel W. H. Meloy although a presentence investigation report by the parole and probations board had recommended probation.

Gilbert broke down and had to be helped from the courtroom after the initial sentencing. Yesterday, her voice breaking, she asked the panel to free her.

"I'm very sorry for what happened," she said, her voice barely above a whisper. "I didn't mean to do it. Everyone's been punished so strongly, so long. We've all tried to be better people and do good things. It's been difficult. Please give us a chance . . ." At that point Gilbert broke down completely.

As Woods delivered the verdict, adding that there would be a five-year probation period and that Gilbert must see a psychiatrist, members of Gilbert's family tearfully hugged one another and the deputy sheriffs who had guarded her during the sentencing shook her hand and congratulated her.

At the same time, the parents of her husband, William Gilbert, got up and walked out of the courtroom.

"All I felt was relief," Gilbert said after a tearful family reunion. "I was thinking I can go home and take care of my children, they need me.All I'm going to do tonight is hug my kids."

Gilbert shot and killed her husband April 14, 1976, moments after he had returned home, allegedly seeking a reconciliation. He had moved in with another woman several weeks earlier.

Moments before William Gilbert arrived, however, the other woman had driven up in his car. As Barbara Jean Gilbert tried to force her way into the other woman's car, her husband arrived and the two struggled briefly. At the end of the struggle, Gilbert went into the house, got a .22 caliber pistol from under a mattress, returned and shot her husband once in the chest.

He died the next day. Gilbert testified that before she shot him her husband had laughed at her, saying, "Come on, go ahead, shoot me, go ahead."

On July 21, 1976, Gilbert was convicted of first degree murder and carrying a deadly weapon and sentenced to life in prison by Judge William B. Bowie.

One month later, her mother hired a new attorney, Joseph DePaul, to represent her daughter. DePaul appealed the sentence, and asked Bowie to release Gilbert on bond, pending the appeal, which Bowie did on Aug. 25, 1976.

On Oct. 21 of that year a panel of three judges - including Meloy, ruled on DePaul's appeal, suspending all but eight years of the sentence. One year later, Chief Judge Ernest A. Loveless Jr. granted a new trial based on DePaul's claim that Gilbert's counsel at the first trial had been incompetent.

The second trial concluded last May 22 when jurors found Gilbert guilty only of involuntary manslaughter, the least serious offense of which they could convict her.

The Parole and Probations Board then recommended that Gilbert be placed on probation because of her "exemplary" record in the two years following her husband's shooting.

Gilbert based her appeal on that report and a letter written by a juror that severely criticized Meloy's decision.

Speaking to the judges, DePaul said, "No matter what happens in this court, Mrs. Gilbert will have to live with this the rest of her life. This is a tragedy for everyone involved.